Psoriasis is a chronic, recurrent, papulosquamous dermatosis, the distinctive lesion being a silvery-grey scaling papule or plaque.
The symptoms of psoriasis are small, flat-topped papules (pimples), which develop into larger plaques, which plaques are dull-red in color, covered and surmounted by fine silvery scales. These scales can become thick parakeratotic horny layers which are very difficult to remove. Upon scraping, the scales can be removed to a certain extent, and a red shining surface appears. These primary afflictions usually occur on the knees, elbows, scalp, hairline, nails, back and neck, although no part of the body is immune. The lesions of psoriasis tend to connect with each other. The skin disorder is chronic; and as yet incurable.
Medical science has not been able to cure psoriasis, but several methods of treatment are known to ease the suffering caused by the disease for a short period of time. These methods generally involve the removal of scales by applying formulations that soften them followed by further treatment of the newly-exposed lesion areas. One such method for the removal of the scales is the application of salicylic acid for periods of up to 48 hours. This is time consuming and dangerous in that salicylic acid, which has toxic properties, is absorbed through the skin. The descaled area is then treated with any of a large number of compounds including tars, corticosteroids and the like to heal the underlying psoriasis lesion.